There are a number of very low-level configuration details which need to
be managed precisely to generate a proper range-diff. In particular,
'diff_options' output format, header suppression, indentation, and
dual-color mode must all be set appropriately to ensure proper behavior.
Handle these details locally in the libified range-diff back-end rather
than forcing each caller to have specialized knowledge of these
implementation details, and to avoid duplication as new callers are
added.
While at it, localize these tweaks to be active only while generating
the range-diff, so they don't clobber the caller-provided
'diff_options', which might be used beyond range-diff generation.
Signed-off-by: Eric Sunshine <sunshine@sunshineco.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
The range-diff back-end allows its heuristic to be tweaked via the
"creation factor". git-range-diff, the only client of the back-end,
defaults the factor to 60% (hard-coded in builtin/range-diff.c), but
allows the user to override it with the --creation-factor option.
Publish the default range factor to allow new callers of the range-diff
back-end to default to the same value without duplicating the hard-coded
constant, and to avoid worrying about various callers becoming
out-of-sync if the default ever needs to change.
Signed-off-by: Eric Sunshine <sunshine@sunshineco.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Just like tbdiff, we now show the diff between matching patches. This is
a "diff of two diffs", so it can be a bit daunting to read for the
beginner.
An alternative would be to display an interdiff, i.e. the hypothetical
diff which is the result of first reverting the old diff and then
applying the new diff.
Especially when rebasing frequently, an interdiff is often not feasible,
though: if the old diff cannot be applied in reverse (due to a moving
upstream), an interdiff can simply not be inferred.
This commit brings `range-diff` closer to feature parity with regard
to tbdiff.
To make `git range-diff` respect e.g. color.diff.* settings, we have
to adjust git_branch_config() accordingly.
Note: while we now parse diff options such as --color, the effect is not
yet the same as in tbdiff, where also the commit pairs would be colored.
This is left for a later commit.
Note also: while tbdiff accepts the `--no-patches` option to suppress
these diffs between patches, we prefer the `-s` (or `--no-patch`) option
that is automatically supported via our use of diff_opt_parse().
And finally note: to support diff options, we have to call
`parse_options()` such that it keeps unknown options, and then loop over
those and let `diff_opt_parse()` handle them. After that loop, we have
to call `parse_options()` again, to make sure that no unknown options
are left.
Helped-by: Thomas Gummerer <t.gummerer@gmail.com>
Helped-by: Eric Sunshine <sunshine@sunshineco.com>
Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
At this stage, `git range-diff` can determine corresponding commits
of two related commit ranges. This makes use of the recently introduced
implementation of the linear assignment algorithm.
The core of this patch is a straight port of the ideas of tbdiff, the
apparently dormant project at https://github.com/trast/tbdiff.
The output does not at all match `tbdiff`'s output yet, as this patch
really concentrates on getting the patch matching part right.
Note: due to differences in the diff algorithm (`tbdiff` uses the Python
module `difflib`, Git uses its xdiff fork), the cost matrix calculated
by `range-diff` is different (but very similar) to the one calculated
by `tbdiff`. Therefore, it is possible that they find different matching
commits in corner cases (e.g. when a patch was split into two patches of
roughly equal length).
Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
